12x+9=-4x^2
The discriminant is:
a. 288
b. 108
c. -132
d. 0

Question

12x+9=-4x^2
The discriminant is:
a. 288
b. 108
c. -132
d. 0

anonymous · Answer

b. 108

anonymous · Answer

Thanks! How'd you get the answer?

anonymous · Answer

no it will be 0

anonymous · Answer

Oh o.k. Can you please explain? I have no clue how to solve :/

anonymous · Answer

Kreshnik were you typing? Nothing showed up :/

anonymous · Answer

$$\Large 12x+9=-4x^2$$

$$\Large 4x^2+12x+9=0$$
now here you got the quadratic equation...

use the formula..

$$\Large x_{1/2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}$$

substitute 

a=4 b=12 c=9

and you'll get...

$$\Large \Delta =b^2-4ac$$

$$\Large \Delta =144-4\cdot 4 \cdot 9$$

$$\Large \Delta =144-144$$

$$\Large \ \Delta =0$$

so when Delta =0  we have only one solution...

and going on with the formula the solution will be

$$\Large x=-\frac32 \quad \quad or \quad \quad  x=-1.5$$

NONE OF THE MULTIPLE CHOICES ...


@Rohangrr  Stop giving blindly answers !

anonymous · Answer

Whoa thanks Kreshnik! Awesome explanation

anonymous · Answer

@mathsux4real Glad to help. :)  ... You're welcome ;)